The invention relates generally to the field of testing human presence at a computing device. In particular, the invention relates to a method and system for testing human presence using touch enabled devices.
CAPTCHA, or “Completely Automated Public Turing Test to tell Computers and Humans Apart” (also known as Turing test) has been used in the field of human computer interaction to verify the presence of a human user when an access to a remote resource is required. Without these programs to test human presence, web sites are at the risk of Distributed Denial of Service (DDoS) attacks and spam. Typically, DDoS occurs when an access to a resource on a server takes place by automated means and simultaneous access is sought by multiple clients. Spam happens when automated programs called “bots” fill web forms that are meant for registration or sign up for the web site, which creates fake users for the web site. As may be apparent, such attacks are undesirable.
CAPTCHA tests involving the use of randomized typography or distorted characters have been in use for web sites on the Internet. These CAPTCHAs have not been very effective, since optical character recognition (OCR) technology is constantly improving, and thereby enabling spammers to predict the randomized typography that was used for CAPTCHA tests. Spammers could therefore answer the CAPTCHA tests by automated means and cause DDoS attacks and spam web sites. Accordingly, there is a need for new methods of CAPTCHA other than randomizing typographical elements to test human presence at a client device.
The advance in input mechanisms has led to a proliferation of touch enabled devices capable of receiving touch input as a primary means to operate the device. As such, there is a need for new methods of generating CAPTCHA tests that can be presented on these touch enabled devices and also take advantage of the capabilities of touch based devices.
While there are methods of generating CATPCHAs that exist for touch enabled devices, problems such as users facing tests that are difficult to solve or that involve complex touch operations still exist. Even though such tests could decrease the success rate of automated programs from automatically answering CAPTCHA test, it is important to consider the difficulty posed to the human users while simultaneously keeping the CAPTCHA tests difficult for automated programs to solve.